I wonder if we will end up in the very odd position of having to help the dictator in some way. An Egyptian commenter at Tom Ricks' blog raised that point.

If the dictator wins and drives out all the open opposition but does not crush the spirit of the opposition, then an insurgency of some kind might begin. That would require a clandestine organization or assistance to establish one. The people in the region who have the most experience with clandestine organizations are not people we like much but because of their experience, organization and money they might gain a lot power within any continuing anti-dictator resistance. If that happened, then what do we do? (I know there are a lot of ifs there.)

Like jcustis says, this will be very messy. But, by doing nothing but talk for so long, this is what we signed up for.